gh-105376: Restore deprecated logging warn() method (#122775)

This reverts commit dcc028d92428bd57358a5028ada2a53fc79fc365 and
commit 6c54e5d72166d012b52155cbf13af9e533290e06.

Keep the deprecated logging warn() method in Python 3.13.

Co-authored-by: Gregory P. Smith <greg@krypto.org>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 3f41442..aa9b79d 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -37,7 +37,7 @@ __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR',
            'captureWarnings', 'critical', 'debug', 'disable', 'error',
            'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass',
            'info', 'log', 'makeLogRecord', 'setLoggerClass', 'shutdown',
-           'warning', 'getLogRecordFactory', 'setLogRecordFactory',
+           'warn', 'warning', 'getLogRecordFactory', 'setLogRecordFactory',
            'lastResort', 'raiseExceptions', 'getLevelNamesMapping',
            'getHandlerByName', 'getHandlerNames']
 
@@ -1530,6 +1530,11 @@ class Logger(Filterer):
         if self.isEnabledFor(WARNING):
             self._log(WARNING, msg, args, **kwargs)
 
+    def warn(self, msg, *args, **kwargs):
+        warnings.warn("The 'warn' method is deprecated, "
+            "use 'warning' instead", DeprecationWarning, 2)
+        self.warning(msg, *args, **kwargs)
+
     def error(self, msg, *args, **kwargs):
         """
         Log 'msg % args' with severity 'ERROR'.
@@ -1906,6 +1911,11 @@ class LoggerAdapter(object):
         """
         self.log(WARNING, msg, *args, **kwargs)
 
+    def warn(self, msg, *args, **kwargs):
+        warnings.warn("The 'warn' method is deprecated, "
+            "use 'warning' instead", DeprecationWarning, 2)
+        self.warning(msg, *args, **kwargs)
+
     def error(self, msg, *args, **kwargs):
         """
         Delegate an error call to the underlying logger.
@@ -2169,6 +2179,11 @@ def warning(msg, *args, **kwargs):
         basicConfig()
     root.warning(msg, *args, **kwargs)
 
+def warn(msg, *args, **kwargs):
+    warnings.warn("The 'warn' function is deprecated, "
+        "use 'warning' instead", DeprecationWarning, 2)
+    warning(msg, *args, **kwargs)
+
 def info(msg, *args, **kwargs):
     """
     Log a message with severity 'INFO' on the root logger. If the logger has